Table 2.

Effect of hypoxia on MMP/TIMP mRNA

MMP/TIMP	Normoxia	Hypoxia	P value
MMP-1 (n = 19)	0.88 (0.23 to 3.58)	1.11 (0.14 to 6.77)	0.475
MMP-3 (n = 16)	0.38 (0.04 to 1.48)	0.21 (0.01 to 1.09)	0.224
MT1-MMP (n = 19)	1.71 (0.03 to 9.13)	2.45 (0.15 to 10.78)	0.009
TIMP-1 (n = 19)	1.31 (0.03 to 18.90)	2.68 (0.01 to 26.08)	0.131
TIMP-2 (n = 19)	2.57 (0.12 to 20.97)	2.20 (0.24 to 18.64)	0.457

Data presented as the median (range) and were analysed by Wilcoxon signed rank test. Rheumatoid arthritis synovial cells were exposed to either 21% oxygen (normoxia) or 1% oxygen (hypoxia) for 24 hours. mRNA levels of matrix metalloproteinase (MMP)-1, MMP-3, MT1-MMP, tissue inhibitor of matrix metalloproteinase (TIMP)-1 and TIMP-2 were measured by quantitative PCR. The change in threshold cycle (ΔCt) values was calculated using the 2-ΔΔ^Ct method against the housekeeping gene acidic ribosomal protein. The fold changes in mRNA levels were related to a reference sample (human cDNA).